Electrophotographic photoreceptor, method of producing electrophotographic photoreceptor, image forming apparatus, and process cartridge

Abstract

An electrophotographic photoreceptor includes a conductive substrate; and a photosensitive layer on the conductive substrate, wherein a layer having an outermost surface of the photoreceptor contains a polymer that is formed by polymerizing a crosslinkable charge transport material having an aromatic group and a —CH 2 OH group, and the layer having the outermost surface satisfies the following Formula (1): (Peak 2)/(Peak 1)≦0.05  (1) wherein Peak 1 represents a peak area of an absorption peak (from about 1550 cm −1 to about 1650 cm −1 ) of stretching vibration of an aromatic group, which is obtained when an infrared absorption spectrum of the layer having the outermost surface is measured, and Peak 2 represents a peak area of an absorption peak (from about 1670 cm −1 to about 1710 cm −1 ) of an aromatic aldehyde, which is obtained when the infrared absorption spectrum of the layer having the outermost surface is measured.

What is claimed is: 
     
       1. An electrophotographic photoreceptor comprising:
 a conductive substrate; and 
 a photosensitive layer on the conductive substrate, 
 wherein: 
 a layer having an outermost surface of the photoreceptor contains a copolymer obtained by polymerizing a crosslinkable charge transport material having an aromatic group and a —CH 2 OH group with a crosslinkable charge transport material having a reactive alkoxyl group; 
 the crosslinkable charge transport material having an aromatic group and a —CH 2 OH group is a compound represented by the following Formula (I-1):
   F 1 —(L 1 —OH) n   (I-1),
 
 where:
 F 1  represents an organic group derived from a compound having a hole transport property and an aromatic group, 
 L 1  represents a linear or branched alkylene group having from 1 to 5 carbon atoms, and 
 n represents an integer of from 1 to 4; 
 
 
 the crosslinkable charge transport material having the reactive alkoxyl group is a compound represented by the following Formula (I-2):
   F 2 —(L 2 —OR) m   (I-2)
 
 where:
 F 2  represents an organic group derived from a compound having a hole transport property, 
 L 2  represents a linear or branched alkylene grow having from 1 to 5 carbon atoms, 
 R represents an alkyl group, and 
 m represents an integer of from 1 to 4; and 
 
 
 the layer having the outermost surface satisfies the following Formula (1):
   (Peak 2)/(Peak 1)≦0.05  (1),
 
 
 where:
 Peak 1 represents a peak area of an absorption peak (from about 1550 cm −1  to about 1650 cm −1 ) of stretching vibration of an aromatic group, which is obtained when an infrared absorption spectrum of the layer having the outermost surface is measured, and 
 Peak 2 represents a peak area of an absorption peak (from about 1670 cm −1  to about 1710 cm −1 ) of aromatic aldehyde, which is obtained when the infrared absorption spectrum of the layer having the outermost surface is measured. 
 
 
     
     
       2. The electrophotographic photoreceptor according to  claim 1 , wherein the layer having the outermost surface layer satisfies the following Formula (2):
   (Peak 2)/(Peak 1)≦0.03  (2).
 
 
     
     
       3. The electrophotographic photoreceptor according to  claim 1 , wherein the compound represented by Formula (I-1) is a compound having a structure represented by the following Formula (II-1): 
       
         
           
           
               
               
           
         
         where:
 Ar 1  to Ar 4  may be the same as or different from each other, and each independently represents a substituted or unsubstituted aryl group; 
 Ar 5  represents a substituted or unsubstituted aryl group or a substituted or unsubstituted arylene group; 
 D represents —(L 1 —OH); 
 each c1 to c5 independently represents 0 or 1; 
 k represents 0 or 1; 
 the total number of D is from 1 to 4; and 
 L 1  represents a linear or branched alkylene group having from 1 to 5 carbon atoms. 
 
       
     
     
       4. The electrophotographic photoreceptor according to  claim 1 , wherein the compound represented by Formula (I-2) is a compound having a structure represented by the following Formula (II-2): 
       
         
           
           
               
               
           
         
         where:
 Ar 6  to Ar 9  may be the same as or different from each other, and each independently represents a substituted or unsubstituted aryl group; 
 Ar 10  represents a substituted or unsubstituted aryl group or a substituted or unsubstituted arylene group; 
 D′ represents —(L 2 —OR); 
 each c6 to c10 independently represents 0 or 1; 
 k′ represents 0 or 1; 
 the total number of D′ is from 1 to 4; 
 L 2  independently represents a linear or branched alkylene group having from 1 to 5 carbon atoms; and 
 R represents an alkyl group. 
 
       
     
     
       5. The electrophotographic photoreceptor according to  claim 1 , wherein in Formula (I-1), the organic group derived from a compound having a hole transport property represented by F 1  is an organic group having a skeleton selected from a triphenylamine skeleton, an N,N,N′,N′-tetraphenyl benzidine skeleton, a stilbene skeleton, or a hydrazone skeleton. 
     
     
       6. The electrophotographic photoreceptor according to  claim 1 , wherein in Formula (I-2), the organic group derived from a compound having a hole transport property represented by F 2  is an organic group having a skeleton selected from a triphenylamine skeleton, an N,N,N′,N′-tetraphenyl benzidine skeleton, a stilbene skeleton, or a hydrazone skeleton. 
     
     
       7. The electrophotographic photoreceptor according to  claim 1 , wherein the copolymer is cured in nitrogen at a temperature of from 120° C. to 160° C. for 20 to 40 minutes. 
     
     
       8. An image forming apparatus comprising:
 the electrophotographic photoreceptor according to  claim 1 ; 
 a charging device that charges the electrophotographic photoreceptor; 
 an exposure device that exposes the charged electrophotographic photoreceptor to form an electrostatic latent image; 
 a developing device that develops the electrostatic latent image with a toner to form a toner image; and 
 a transfer device that transfers the toner image from the electrophotographic photoreceptor to a recording medium. 
 
     
     
       9. A process cartridge comprising:
 the electrophotographic photoreceptor according to  claim 1 ; and 
 at least one device selected from a group consisting of a charging device that charges the electrophotographic photoreceptor, an exposure device that exposes the charged electrophotographic photoreceptor to form an electrostatic latent image, a developing device that develops the electrostatic latent image with a toner to forms a toner image, and a cleaning device that removes a residual toner on the surface of the electrophotographic photoreceptor.